A reciprocating compressor cylinder valve, typically recommended for use in slow speed (less than 600 rpm), high differential pressure (up to 30 Mpa [4350 psi]), or high discharge pressure applications (up to 60 Mpa [8700 psi]). Ring valves are comprised of one or more narrow sealing rings arranged concentrically about the center line of the valve. These valves have the advantage of a low-stress levels due to the lack of stress concentration points. An inherent disadvantage of a ring valve is its difficulty to maintain uniform valve flow control due to the independent sealing rings.
See also Valve (Reciprocating Compressor).